Viscoplastic deformations and compressive damage in an A359/SiCp metal–matrix composite

Recent work by the authors has examined the high-strain-rate compression of a metal–matrix composite consisting of an A359 Al alloy matrix reinforced by 20 vol.% of silicon carbide particulates (SiCp). The work-hardening that is observed in the experiments is much lower than that predicted by analytical and computational models which assume perfect particle–matrix interfaces and undamaged particles. In this work, we show that the discrepancy is a result of particle damage that develops within the A359/SiCp composite under compression. The evolution of particle damage has been characterized using quantitative microscopy, and is shown to be a function of the applied strain. A simple analytical model that incorporates evolving damage within the composite is proposed, and it is shown that the analytical predictions are consistent with the experimental observations over a wide range of strain rates.